I purchased two M400A2s for $50, NOS from a seller by me. Both are from PA Turnpike maintenance overstock, though one was made in 2008 whilst the other was made in 1996. I also have one from @Metal Halide Boy and will still be picking up the one from the seller I bought the OV-25 from free of charge.

If anyone has interest in an M400A2 multi-volt 400W HPS luminaire, do reach out. One thing is, I do not have a refractor for the one I got from Metal Halide Boy as both units broke in shipping. Though, there are some cheapish ($50) glass refractors for sale on eBay. Thanks.

...and if anyone needs some GE 510 refractors for the M400A2's posted above...
https://www.ebay.com/itm/387626986950
https://www.ebay.com/itm/266897748260

Thanks.

All of the luminaires have glass except for the M400R2 (it's single, not split door)

Do the M400A2 and R2 use the same refractor? I still need to hunt some up for 4 M400R2's that I have left.

Correct, the R2s and A2s refractors are interchangeable.

where these the ones on facebook marketplace? If so how much for one as i was hoping to get one

Yeah, these were off of Marketplace in Newtown, Pennsylvania. I can send you one, but just a fair warning- the refractors are quite fragile and have a high probability of breaking in transit. Metal Halide Boy sent me two refractors, both of which broke in transit.

I'm pretty sure I could have shipped them without them breaking if I had used a grossly oversized box with a ton of packaging/ bubble wrap. But it would have been expensive... So I tried having UPS package them for me. Which evidently was a mistake as well.

Anyway does anyone know if the M400R3 uses the same refractor as the R2 and A2? I'm pretty sure it does not...

The R3 is completely different...has the same footprint as an AEL 125. There's some available on eBay.
As to refractors surviving shipping, it can be done...the box has to be oversized and with no voids...that's what kills a refractor.

@BT25 , I genuinely used to think that the M400R3 was a blatant knockoff of the 125. Driving towards Philadelphia on i-95 as a kid, I'd recall seeing them sprinkled amongst M400As and M400A2s, and remember thinking to myself how similar yet strangely different this light is to (what I now know is) the 125. I always thought the R3 looked a little "angry". 

@Maxim - Funny, I thought the AEL Series 125s were a knockoff of the M-400s lol. The AEs weren't as common as the GEs around my area and every time I saw one, I thought they looked incomplete compared to the GEs when I was younger. Same thing with the M-400A and Series 325s.

@fluorescent lover 40 , for us over here, the 125 was more popular. Interesting how quantity of product affects one's intuition. 

Also, yeah, the 325 has always looked a little half-baked... 

@Maxim: you sure about that?

The R3 is completely different...has the same footprint as an AEL 125. There's some available on eBay.
As to refractors surviving shipping, it can be done...the box has to be oversized and with no voids...that's what kills a refractor.

That's exactly what I thought... Thanks!